Medicament Delivery Device Comprising a Locking Mechanism Having a Lever

ABSTRACT

Medicament delivery device comprising a movable guard ( 10 ) being movable between a proximal and a distal position and a locking mechanism ( 15 ) having a level ( 16 ), the lever ( 16 ) restricting movement of an actuation locking member ( 24 ) until the movable guard is positioned in a distal position and the lever ( 16 ) restricting movement of the guard ( 10 ) in a proximal position after actuation of the device.

TECHNICAL FIELD

The present invention relates to a medicament delivery device, forexample for injection, having a locking mechanism. More specifically,the present invention relates to a medicament delivery device forauto-injection having a mechanism for inhibiting dose delivery until thedevice is positioned at a dose delivery site and/or for locking a guardin a proximal position after a dose is delivered, the mechanismcomprising a ledge.

RELATED ART

Medicament delivery devices for automatic or semi-automatic injection ofmedicaments have been known for many years. While the first generationsof injectors merely aimed to deliver a medicament as quickly aspossible, increased use of the devices by patients in non-clinicalsettings has lead to the necessity of providing further handling andsafety functions.

Important handling and safety functions of medicament delivery devicesinclude inhibiting premature actuation of the device (misfiring). Toensure that the medicament is properly injected, actuation of the deviceis inhibited until the auto-injector is correctly positioned at a dosedelivery site. Furthermore, since the member delivering the medicamentcan be sharp and may be contaminated after the device has been actuated,devices that retract or cover the medicament delivery member when thedevice is withdrawn from the dose delivery site have been developed. Toprevent that a person unintentionally contacts the medicament deliverymember and to allow safely discarding the device, some devices feature amechanism that locks the device once the medicament delivery member iscovered or retracted.

WO 02/047746 discloses a medicament delivery device comprising a housingarranged to contain a medicament container, a needle cover surrounding aneedle and spring means. The spring means may push the needle past theend of the needle cover and operate the medicament container to supply adose of medicament. Furthermore, the device comprises first lockingmeans locking the spring means in a pressurized state. The first lockingmeans may be released by first activating means, which may be manuallyoperated. The first activating means are locked by second locking means,which are released by second activating means when the needle cover isexposed to pressure by the medicament delivery device being positionedat the dose delivery site, When the patient withdraws the injector fromthe dose delivery site, further spring means push the needle cover outof the housing. A lock ring having arms that engage openings in thehousing is provided to prevent the needle cover being pushed in again.Although the medicament delivery device provides all necessaryfunctions, several mechanism are necessary to achieve this objective.

WO 2004/060445 discloses a safety system for a syringe. The system mayforcefully inject a syringe when an actuator contacts the dose deliverysite and withdraw the syringe into a housing when injection iscompleted. However, the needle and the guard can be moved, allowing forthe needle to be contacted even after it is retracted into the housing.Therefore, WO 2004/060445 proposes the use of end covers for safedisposal of the system.

WO 2006/118616, which relates to a needle-less injector device,discloses a mechanism for inhibiting actuation of the device until thedevice is positioned against the skin. However, also in this case themechanism disclosed is not designed to prevent users or third personsfrom unintentionally contacting the medicament delivery member after thedevice is actuated.

As shown above, available medicament delivery devices do either notprovide the necessary handling and safety functions or requirecooperation of one or several complex mechanisms. Therefore, some of thepresent devices are not safe, while others are costly to produce anddifficult to assemble. Accordingly, there is a need for medicamentdelivery devices that comprise mechanisms providing some or all of thesefunctions with as few parts as possible and in a reliable manner.

SUMMARY OF THE INVENTION

In order to overcome one or several of the above-mentioned problems,medicament delivery device according to the independent claims areprovided.

Further aspects, improvements and variations are disclosed in thedependent claims, the figures and the description.

The medicament delivery device of the present invention allowsinhibiting actuation of the device until the device is positioned at adose delivery site. Furthermore, a medicament delivery device isprovided wherein the medicament delivery member is safely covered afteractuation of the device. The device can thus be stored or discarded in asafe way. These advantages are achieved by providing a medicamentdelivery device with an improved locking mechanism. The lockingmechanism of the inventive medicament delivery device provides one orseveral of the functions in a reliable and safe manner and requires aminimal amount of elements. The locking mechanism is easy to assembleand the medicament delivery device can be manufactured cost-effectively.

In the present application, when the term “distal” is used, this refersto the direction pointing away from the dose delivery site. When theterm “distal part/end” is used, this refers to the part/end of thedelivery device, or the parts/ends of the members thereof, which is/arelocated furthest away from the dose delivery site. Correspondingly, whenthe term “proximal” is used, this refers to the direction pointing tothe dose delivery site. When the term “proximal part/end” is used, thisrefers to the part/end of the delivery device, or the parts/ends of themembers thereof, which is/are located closest to the dose delivery site.

According to independent claim 1, a medicament delivery device isprovided. The medicament delivery device comprises a moveable guard thatis movable between a proximal position and a distal position and alocking mechanism having a lever. The lever restricts or locks themovement of an actuation locking member until the movable guard ispositioned in a distal position and the lever restricts or locks themovement of the guard in a proximal position after the device isactuated. So, both of these functions may be provided by a singlelocking mechanism, e.g., a lever. The lever may be a see-saw.

According to a further embodiment of the present invention, a medicamentdelivery device for auto-injection comprises a movable guard beingmovable between a proximal and a distal position and a locking mechanismhaving a see-saw is provided. The see-saw restricts movement of anactuation locking member until the movable guard is positioned in adistal position and/or the see-saw restricts movement of the guard in aproximal position after the device is actuated. Any feature describedbelow may also be provided with this embodiment of the invention. Inparticular, any feature relating to the lever may equally be providedfor the see-saw.

The lever or the see-saw may be pivotally mounted in any member of themedicament delivery device. Preferably, the lever or the see-saw isformed integrally and pivotally with any member of the device. Morepreferably, the lever or the see-saw is formed integrally with amedicament container holder. The lever or the see-saw preferably isprovided such that it can be pivoted or deflected around its pivotalaxis in both directions.

In the context of the present invention, the term “guard” denominates amember for covering a medicament delivery member. The guard preferablyis contacted when the device is positioned at the dose delivery site.Furthermore, the guard preferably covers the medicament delivery memberwhen the device is withdrawn from the dose delivery site at least afterthe device has been actuated. Preferably, after actuation of the devicethe guard is moved to and locked in a position covering the medicamentdelivery member. Hence, the guard according to the invention is movableor displaceable. More preferably, after the device has been actuated,the guard is moved and locked in a proximal position when the device iswithdrawn from the dose delivery site. The guard preferably is urged ina proximal direction by the force of a spring. The spring may beprovided at the proximal end of the guard. The spring may be formedintegrally with the guard. Thus, the guard is a protection element, suchas a needle protection element or needle protection sleeve that protectsthe user against inadvertently or accidentally getting in contact withthe needle which may be contaminated.

A medicament delivery member may be any member through which amedicament is delivered. For example, the medicament delivery member maybe a needle or a nozzle, e.g., a needle-less injection nozzle. Themedicament delivery member may be formed integrally with a medicamentcontainer or be an independent element of the device. Preferably, themedicament delivery member is covered or retracted until the medicamentdelivery device is actuated and may not be unintentionally contacteduntil this moment. For example, the medicament delivery member may beretracted in the medicament delivery device.

According to any embodiment of the present invention, the medicamentdelivery device may comprise an actuation mechanism and/or an actuationlocking member. An actuation mechanism is a mechanism that actuates thedevice to deliver a dose. Preferably, the actuation mechanism actuatesthe device by releasing spring means from a pressurized state, thespring means being capable of pushing the medicament delivery memberpast the end of the needle cover and/or operating a medicament containerto provide a dose of medicament. Preferably, the actuation mechanismactuates the device when activated by a user. The actuation mechanismpreferably is activated when the user presses a push button. The pushbutton may be located at the distal end of the device. In an example,the push button is pushable in a longitudinal direction of themedicament delivery device. In another example, the push button is firstrotatable around the longitudinal axis of the medicament delivery deviceand subsequently pushable in longitudinal direction of the medicamentdelivery device. Instead of being in the form of a button, it may havethe form of a sleeve. In another example, the push button is pushabletransverse to the longitudinal axis of the medicament delivery device.Instead of a pushable button a rotary knob may be used.

In any embodiment of the present invention, the actuation mechanismpreferably can only be activated when certain conditions are fulfilled.Preferably, the actuation mechanism is locked and can not be actuateduntil the device is positioned at a dose delivery site. For this purposethe device may comprise an actuation locking member locking actuation ofthe device. The actuation locking member may lock actuation of thedevice by locking the actuation mechanism and/or by locking anothermember and thereby inhibiting that the actuation mechanism is activated(e.g., unintentionally). Preferably, the actuation locking member locksactuation of the device by restricting the movement of a member or partof the actuation mechanism or of the entire actuation member. Forexample, the actuation locking member may have distally directed armsabutting protrusions of a member of the actuation mechanism.

When the actuation locking member restricts the movement of a member orpart of the actuation mechanism, the actuation mechanism may be lockedby restricting the movement of the actuation locking member. In anyembodiment of the present invention the actuation mechanism and/or theactuation locking member may be provided such that actuation of themedicament delivery device is inhibited until the device is positionedat the dose delivery site. Preferably, actuation of the device isinhibited until a guard, e.g., a needle protection sleeve, that contactsthe dose delivery site is moved or displaced and reaches a distalposition.

According to any embodiment of the invention the actuation mechanism maycomprise a medicament delivery drive unit for expelling the medicamentfrom the medicament delivery device. The drive unit may include aplunger member. At least one spring for spring-loading the plungermember may be provided around the plunger member or in a hollow spacethereof. The plunger member may be spring-loaded by the spring beingcompressed or elongated.

The medicament delivery drive unit may further comprise a drive springholder for holding the compressed or elongated spring. The drive springholder may be configured to partially surround the spring-loaded plungermember. Preferably, the drive spring holder is generally U-shaped andhas at least one, preferably two proximally directed leg. Each leg maycomprise a radial outwardly extending ledge.

The medicament delivery drive unit may further comprise connection meansfor holding the spring-loaded plunger member in a pre-loaded state. Forthis purpose the connection means may be arranged with a distallydirected arm, which may be flexible in the radial direction. Preferably,the distal end of the arms is arranged with an inwardly directed hook.The hook may be configured to fit into at least one cut-out of theplunger member or a plunger rod. Preferably, two distally directed armsare provided, each having one inwardly directed hook. Preferably, thedrive spring holder is axially arranged through the connection means.

Furthermore, the actuation mechanism may comprise at least one member ofthe actuation mechanism for releasing the connection means from thespring-loaded plunger member or the plunger rod. The member may beco-axially slidable on the connection means.

Preferably, the drive spring is compressed between a proximal inner endsurface of the plunger member and drive spring holder when themedicament delivery drive unit is assembled. More preferably, the drivespring is compressed between a proximal inner end surface of the plungermember and a transversal contact end of the drive spring holder. Theradial outwardly extending ledges of the of the drive spring holder maybe engaged to the proximal annular surface of the connection means forpreventing the drive spring holder from being moved in the distaldirection by the spring. The member of the actuation mechanism may bearranged surrounding the distally directed arms of the connection meanssuch that the hooks of the arms are engaged in a correspondingengagement with a cut-out on the plunger member.

Initial Position

According to any embodiment of the present invention, the movement ofthe actuation locking member may be restricted by a locking mechanism ora lever at least in a certain direction, preferably the proximaldirection. Preferably, the movement of the actuation locking member isrestricted when the lever is an initial position. The initial positionpreferably is the first position of a dose delivery cycle. Morepreferably, the initial position is a position in which the device isready for being used but the actuation mechanism may not be activated.The initial position may be a position in which no force orsubstantially no force acts on the lever and/or in which the lever isnot overlapped by members that may overlap the lever.

In order to restrict the movement of the actuation locking member, thelever may have any suitable shape. Preferably, the lever comprises atleast one first portion and at least one second portion, the secondportion being positioned further from a plane which is parallel to thelongitudinal axis of the medicament delivery device and includes thepivotal axis about which the lever pivots than the first portion whenthe lever is in the initial position. Assuming a generally elongated orcylindrical shape of the medicament delivery device, said plane is atangential plane to the outer surface of the medicament delivery device,i.e., of its housing, or parallel to such tangential plane. The secondportion is raised or projected relative to said plane. For example, thelever may be curved or pivoted. More preferably, the lever comprises asecond portion that is thicker than a first portion. Most preferably,the lever comprises a second portion having a ledge The pivotal axis ofthe lever may be considered are border line or boundary between thefirst portion (being proximal form such line) and the second portion(being distal from the line).

According to any embodiment of the invention, it is preferred that themovement of the actuation locking member towards or into the positionreleasing the actuation mechanism is restricted by the actuation lockingmember abutting the lever when the lever is in the initial position.Preferably, the actuation locking member abuts at least a part of thesecond portion of the lever. More preferably, the movement of theactuation locking member is restricted because the actuation lockingmember abuts one of the portions of the lever that is thicker than theothers. Most preferably, the movement of the actuation locking member isrestricted by the actuation locking member abutting the ledge of thelever. Thus, the lever provides a locking function locking the actuationlocking member in its initial position.

In any embodiment of the invention the actuation locking memberpreferably is provided distal of the lever. Accordingly, it is preferredthat at least a part of the portion of the lever against which theactuation locking member abuts is provided at or close to the distal endof the lever. Preferably, at least a part of the second portion of thelever is provided distal of at least a part of the first portion of thelever, the second portion being positioned further from the plane thatis generally parallel to the longitudinal axis of the medicamentdelivery device and including the pivotal axis about which the leverpivots than the first portion when the lever is in the initial position,as defined above. More preferably, at least a part of the second portionis provided distal of the pivotal axis of the lever and at least a partof the first portion is provided proximal of the pivotal axis of thelever. The pivotal axis is preferably perpendicular to the longitudinalaxis of the medicament delivery device while being offset from thelongitudinal axis. Assuming a generally elongated or cylindrical shapeof the medicament delivery device, the pivotal axis may be a tangentialto the outer surface of the medicament delivery device, i.e., of itshousing, or parallel to such a tangential.

According to any embodiment of the invention, the guard preferably canbe moved in at least one direction when the lever is in the initialposition. Preferably, the guard can be moved in the distal direction.More preferably, the guard is moved in the distal direction when themedicament delivery device is pressed against the dose delivery site.Most preferably, the guard reaches a distal position when the medicamentdelivery device is correctly positioned at the dose delivery site. Theguard preferably is moved in the distal direction against the force of aspring. The spring may be provided at the distal end. The spring may beintegral with the guard.

Tensioned Position

When the guard moves, preferably, when the guard is moved or displacedin a distal direction, the guard or a member moved by the guardpreferably overlaps at least a portion of the lever. Preferably, theguard or the member moved by the guard first overlaps at least a part ofa first portion of the lever and subsequently overlaps at least a partof a second portion of the lever, the first portion being positionedcloser to the plane which is generally parallel to the longitudinal axisof the medicament delivery device and includes the pivotal axis aboutwhich the lever pivots than the second portion when the lever is in theinitial position, as defined above. Preferably, the guard or the membermoved by the guard overlaps at least a part of the first portion that isprovided proximal of the second portion first. More preferably, theguard or the member moved by the guard first overlaps a proximal portionof the lever and subsequently overlaps a distal portion of the lever.Most preferably, the guard or the member moved by the guard firstoverlaps at least a part of the first portion that is provided proximalof the pivotal axis of the lever and subsequently overlaps at least apart of the second that is positioned distal of the pivotal axis of thelever. Preferably, the lever has the general shape of a beam with afirst and a second portion, the first portion being thinner than thesecond portion. When the guard or a member moved by the guard moves in adistal direction, preferably at least a part of the thinner portion thatis provided proximal of the pivotal axis of the lever is overlappedfirst. Preferably, the guard slides over the lever, such as a sleeve.More preferably, the guard can slide over the second portion, thethicker portion or the ledge of the lever, because this portion and/orthe portion of the guard or the member moved by the guard that contactsthis portion is wedge-shaped.

Since the proximal portion of the lever is overlapped by the guard, thelever cannot pivot when a force is exerted on the distal end, forexample, by tongues exerting a force on the distal end of the lever whenthey overlap the ledge and press the distal end inwards. Thus the lever,preferably in the form of a beam, will be tensioned due to the positionof the guard.

Such beam may be connected at the middle thereof o a medicamentcontainer holder by two pivot arms so that a proximal end and a distalend of the beam are defined. The beam may be formed integral with themedicament delivery container or pivotally engaged therewith. The distalend of the beam may be arranged with a transversally extending ledgeextending on both sides of the beam. The guard may be arranged such inrelation to the beam that the tongues are positioned on each side of thebeam.

When the guard overlaps the lever in the manner described, the guardpreferably exerts a force on the distal portion of the lever and/ortensions the lever. In response, the lever—being sufficientlyflexible—preferably is bent or deflected such that it does not abut theactuation locking member anymore. The lever preferably no longer abutsthe actuation locking member when the guard reaches a distal position.The guard preferably reaches the distal position when the medicaldelivery device is correctly positioned at the dose delivery site. Thedistal position preferably is a position in which the guard ispositioned such that the medicament delivery member can deliver a doseif the medicament delivery device is actuated.

When the lever does not abut the actuation locking member any longer dueto being bent or deflected or pivoted, the actuation locking memberpreferably can move in at least a certain direction in which the leverrestricts movement as long as it abuts the actuation locking member.Preferably, the actuation locking member can be moved in a proximaldirection. When the movement of the actuation locking member is notrestricted at least a certain direction, preferably the proximaldirection, the medical delivery device preferably can be actuated. Morepreferably, the device can be actuated by activating the actuationmechanism.

When the actuation locking member can be moved in a proximal direction,preferably also a member of the actuation mechanism can move. When move,the member of the actuation mechanism preferably slides along the armsof the connection means such that the at least one arms of theconnection means is free to move through at least one recesses of themember of the actuation mechanism in a radial direction. This preferablycauses the hooks of the connection means to move out of contact or itsresilient engagement with the cut-outs of the spring-loaded plungermember or the spring-loaded plunger rod. This preferably releases thespring-loaded plunger member or the spring loaded plunger rod to move inthe proximal direction due to the force of the compressed spring of themedicament delivery drive unit. The movement of the spring-loadedplunger member or the spring loaded plunger rod then may force thestopper to move proximally and thereby expel the medicament through themedicament delivery member. The medicament delivery operation may becompleted when the stopper has reached its end position, for example theproximal end position inside the medicament container. The arms of theconnection means may be configured such that the push button is lockedin a proximal and depressed position when the device has been actuated.For example, the member of the actuation mechanism may have at least onerecess through which the at least one arm of the connection meansextends and engages the push button.

When the guard is moved, preferably when the guard is moved to thedistal position, the guard or the member moved by the guard preferablycontacts and/or overlaps certain portions of the lever but does notcontact and/or overlap the entire lever. In particular, the guardpreferably does not contact and/or overlap the entire second portion ofthe lever. The guard may have distally extending tongues and/or portionsof different radial thickness. Preferably, the guard has two distallyextending tongues. The tongues may be attached to or made integral withthe distal end of the guard. For example, the tongues extend inlongitudinal direction towards the distal end of the device like thelegs of a U. The lever may have the shape of a beam having a proximalend and a distal end. Preferably, at least a part of the second portionof the lever is provided at or close to the distal end of the lever.More preferably, the lever is thicker at or close to the distal end and,most preferably, the lever has a transversally extending ledgepositioned at or close to the distal end. The ledge may extendtransversally (relative to the longitudinal axis of the beam ormedicament delivery device) to both sides of the beam.

According to any embodiment of the present invention, the lever may alsobe overlapped by a member upon actuation of the device. Preferably, thelever is overlapped by the actuation locking member. More preferably,the lever is overlapped by the actuation locking member moving into adirection in which the lever restricts its movement when it is in theinitial position. Most preferably, the lever is overlapped by theactuation locking member moving in the proximal direction.

The member overlapping the lever when the device is actuated preferablyoverlaps at least a part of the second portion of the lever. Morepreferably, the member overlaps at least a part but not the entiresecond portion of the lever. Most preferably, the member overlaps and/orcontacts a part of the second portion of the lever not being overlappedby the guard or a member moved by the guard when the guard is in thedistal position. The member overlapping the lever upon actuation of thedevice, preferably the actuation locking member, may have one or severallongitudinally extending tongues and/or portions of different radialthickness. Preferably, the proximal portion of the actuation lockingmember is ring-shaped (such as a sleeve-like structure) or a ring-shapedmember, allowing the actuation locking member to slide along themedicament container holder. Preferably, one or several longitudinallyextending tongues or extensions in proximal direction are provided atthe proximal end of the actuation locking member. The tongues may beattached to or made integral with the proximal end of the actuationlocking member. More preferably, one tongue is provided.

Alternatively, two tongues or three tongues are provided. The actuationlocking member preferably is adapted to overlap and/or contact otherparts of the lever than those contacted by the guard or a member movedby the guard. Most preferably, the longitudinally extending tongues ofthe actuation locking member and of the guard are adapted for theactuation locking member and the guard or a member moved by the guardbeing slit into each other. Seen in circumferential direction of themedicament delivery device, the tongues of the actuation locking memberhave a space or gap inbetween, and the tongues of the guard are alsospaced from each other by a gap. Relative to each other, the tongues ofthe actuation locking member are in circumferential positionscorresponding to the circumferential positions of the gaps between thetongues of the guard so that tongues extend into corresponding gaps.

In other words, the ring-shaped part or member of the actuation lockingmember may have at least one proximally extending tongue arranged inline with the beam of the locking mechanism. The ring-shaped member mayfurther be arranged with distally directed arms. The distal parts of thearms may extend into longitudinal grooves of a guide sleeve of theactuation mechanism. At the distal end of these longitudinal grooves,transversal grooves may be arranged. A further member of the actuationmechanism may be provided inside the guide sleeve. The member maycomprise a generally tubular proximal part arranged with protrusions onits outer surface, these protrusions fitting into the grooves of theguide sleeve. Further, the tubular part of the member may extend in thedistal direction into a push button, which protrudes through an openingat the distal end of the device.

Thus, when the lever or beam of the locking mechanism is in the initialposition, the push button may not be depressed because the proximallydirected tongue of the actuation locking member abuts against the ledgeof the beam and is restricted from moving in the proximal direction.Since the distal ends of the arms are placed in the longitudinalgrooves, they are in the way for the protrusions. Thus the actuationmechanism can not be activated and the device is locked againstactuation.

According to any embodiment of the present invention, the lever may bereleased from tensioning when the guard or a member moved by the guardis moved in a proximal direction. Preferably, the lever is released fromtensioning when the guard is moved to a proximal position. The proximalposition preferably is a position in which the guard covers themedicament delivery member but no longer overlaps the lever. Preferably,the guard or the member moved by the guard is moved in a proximaldirection by a spring arranged for urging the guard in the proximaldirection. The spring preferably urges the guard in a proximal directionwhen the medical delivery device is withdrawn from the dose deliverysite. When the lever is overlapped by a further member while beingtensioned, preferably when the lever is overlapped by the actuationlocking member while being tensioned, releasing the tensioning of thelever may lead to the lever being positioned in a final position.

Final Position

According to any embodiment of the invention, the movement of the guardmay be restricted by the lever at least in a certain direction,preferably the distal direction. More preferably, the movement of theguard in the distal direction is restricted when the guard reaches aproximal position after the device has been actuated. Preferably, thelever restricts the movement of the guard when the lever is in the finalposition. The final position preferably is the last position of thelever in a dose delivery cycle. More preferably, the final position is aposition in which the device has been actuated and a dose has beendelivered. Preferably, the final position is a position in which theactuation locking member at least partly overlaps and/or contacts thelever. More preferably, the final position is a position in which theactuation locking member at least partly overlaps and/or contacts thedistal portion of the lever. Most preferably, the final position is aposition in which the actuation locking member at least partly overlapsthe second portion of the lever. Even more preferably the final positionis a position in which the actuation locking member at least partlyoverlaps and/or contacts a portion of the lever against which it abutsin the initial position. The final position may be a position in whichthe lever is pivoted in response to a force on the distal portion of thelever and/or a position that is reached when the lever is released fromtensioning.

When the lever is in the final position, movement of the guardpreferably is restricted by the guard or a member moved by the guardabutting against at least a portion of the lever. Preferably, the guardabuts against a proximal portion (the first portion) of the lever. Morepreferably, the guard abuts against a proximal end of the lever. In thefinal position the guard preferably abuts against a portion of the leverthat it overlaps when the lever is tensioned.

Thus, the proximal movement of the spring will cause it to release theproximal end of the beam, whereby the latter will flex outwards in theradial direction due to the tension built up in the beam. The lever,preferably beam, may thus reach the final position in which the leverrestricts the movement of the guard in the distal direction. Theproximal end of the longitudinal beam may be positioned between thedistally directed tongues of the guard, locking the guard againstmovement in the distal direction and allowing the device to be discardedsafely.

According to any embodiment of the invention, the actuation lockingmember preferably abuts the lever when the lever is in the initialposition and is slidable over the lever when the lever is tensioned.Furthermore, also according to any embodiment of the invention, theguard preferably is slidable over the lever when the lever is in theinitial position and abuts against one of the portions of the lever whenthe lever is in the final position.

The locking mechanism and/or the medicament delivery device may beconfigured such that the guard can be unlocked in order to start a newdelivery cycle. Preferably, the medicament delivery device is configuredas a disposable single-use device and the guard can not be unlockedwithout the device being destroyed or disassembled.

The medicament delivery device may be further arranged with a technicalfeature to indicate and thereby inform the user when a dose deliveryoperation is completed. The technical feature may be arranged togenerate an audible signal in response to a signal indicative of thecompleted delivery operation. For this purpose, at the end of themedicament delivery sequence, the distal end of the spring-loadedplunger member or the spring-loaded plunger rod may pass out theproximal end of the at least one arm of the drive spring holder. Therebythe arm and thus the ledge of the drive spring holder may be free tomove radially inwards. Due to a remaining force of the spring of themedicament delivery drive unit acting on the drive spring holder, thelatter may be moved in the distal direction until the drive springholder contacts a distal inner end surface of the connection means. Whenthe spring holder contacts the end surface, an audible signal may beproduced, indicating to the user that the device may be withdrawn fromthe delivery site and discarded it in a safe manner.

The lever of any of the embodiments described may be a see-saw.

BRIEF DESCRIPTION OF THE DRAWINGS

The following Figures below disclose an embodiment of the invention forillustrational purposes only. In particular, the disclosure within theFigures is not meant to limit the range of protection of the invention.The embodiment shown may be modified in many ways within the scope ofthe claims.

FIG. 1 : Exploded view of the medicament delivery device of the presentinvention.

FIG. 2 : Locking mechanism of a medicament delivery device of thepresent invention, the lever being shown in the initial position.

FIG. 3 : Enlarged view of the locking mechanism, the lever being shownin the initial position;

FIG. 4 : Locking mechanism of a medicament delivery device of thepresent invention, the lever being tensioned and overlapped by theguard.

FIG. 5 : Locking mechanism of the medicament delivery device of thepresent invention, the lever being overlapped by the guard and theactuation locking member.

FIG. 6 : Locking mechanism of the medicament delivery device of thepresent invention, the lever being in the final position.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an exploded view of a medicament delivery device accordingto the present invention. The device comprises a guard 10 or sleeve-likestructure slidable in the longitudinal direction inside a generallycylindrical housing 11. A spring 13 may be arranged for urging the guard10 in the proximal direction.

The guard 10 may comprise at least one distally directed tongue or mayhave portions of different radial thickness attached to or made integralwith the distal end of the guard 10. For example, as shown in FIG. 2 ,the guard 10 may comprise at least two distally directed tongues 12 madeintegral with the distal end of the guard 10. A medicament containerholder 14 for holding a medicament container 70 may be arranged in theguard 10. The medicament container may comprise a medicament deliverymember. However, the medicament delivery member does not have to be partof the medicament container and may be an independent element of thedevice. As shown in FIG. 1 , the medicament delivery member may be aneedle 71.

A side surface of the medicament container holder 14 may be arrangedwith a locking mechanism 15. The locking mechanism 15 comprises a lever.The lever may be a see-saw. The lever may have the form of alongitudinally extending beam 16. The beam 16 may be connected at themiddle thereof to the medicament container holder 14 by two pivot arms18, creating a proximal end 19 and a distal end 20. The beam may beformed integral with the medicament delivery container 14 or pivotallyengaged therewith. The distal end 20 of the beam 16 may be arranged witha transversally extending ledge 22 extending on both sides of the beam16. The guard 10 may be arranged such in relation to the beam 16 thatthe tongues 12 are positioned on each side of the beam 16, as will beexplained further below.

Furthermore, the device may be provided with an actuation locking member24. The actuation locking member 24 may comprise a generally ring-shapedor sleeve-shaped member 26 surrounding the medicament container holder14 and positioned distally in relation to the beam 16. The ring-shapedmember 26 may have at least one proximally extending tongue 28 arrangedin line with the beam 16. The ring-shaped member 26 may further bearranged with distally directed arms 30. As shown in FIG. 2 , the distalparts of the arms 30 may extend into longitudinal grooves 32 of a guidesleeve 34. A member 38 of an actuation mechanism 37 may be providedinside the guide sleeve 34. The member 38 may comprise a generallytubular proximal part arranged with protrusions 40 on its outer surface,protrusions 40 fitting into the groove 32 of the guide sleeve 34.Further, the tubular part of the member 38 may extend in the distaldirection forming a push button 42, which protrudes through an openingat the distal end of the guide sleeve 34.

The actuation mechanism 37 may further comprise a medicament deliverydrive unit 50 having an plunger member or an elongated plunger rod (notshown). The plunger member may be provided with a hollow space intowhich a drive spring 52 is arranged to spring-load the plunger. Theproximal end of the elongated plunger rod may be in contact with astopper of the medicament container 70. The medicament delivery driveunit further may comprise a drive spring 52 acting on the plunger rod. Adistal end of the spring may be in contact with a drive spring holder 54having a general U-shape.

The drive spring holder 54 may have distally directed legs and each legmay comprise a radial outwardly extending ledge. The drive spring holder54 may be configured to partially surround the spring-loaded plungermember.

The medicament delivery drive unit may further comprise connection means56. The connection means 56 may be arranged with two distally directedarms 58, which may be flexible in the radial direction. The distal endsof the arms 58 may be arranged with inwardly directed hooks 60. Thehooks 60 may be designed to fit into cut-outs of the plunger rod to holdit in position, as will be explained. The drive spring holder 54 may beaxially arranged by the connection means 56. The member 38 may beco-axially slidable on the connection means 56.

When the medicament delivery drive unit is assembled, the spring 52 maybe compressed between a proximal inner end surface of the plunger memberand a transversal contact end of the drive spring holder 54. The radialoutwardly extending ledges of the of the drive spring holder 54 may beengaged to the proximal annular surface of the connection means 56 forpreventing the drive spring holder from being moved in the distaldirection by the drive spring. The member 38 may be arranged surroundingsaid distally directed arms 58 such that the hooks 60 are engaged in acorresponding engagement with a cut-out on said spring-loaded plungermember.

As shown in FIG. 2 , when the lever of the locking mechanism 15 is inthe initial position, the push button 42 may not be depressed becausethe proximally directed tongue 28 of the actuation locking member 24abuts against the ledge 22 of the beam 16 and is restricted from movingin the proximal direction. Since the distal ends of the arms 30 areplaced in the longitudinal grooves 32, they are in the way for theprotrusions 40. Thus the member 38 cannot be activated and the device islocked against actuation.

The next step is to perform a dose delivery. This is done by pressingthe proximal end of the guard 10 against a dose delivery site. Thiscauses the guard 10 to slide in the distal direction of the device,whereby the distally directed tongues 12 will be moved in contact withthe ledge 22. Since the ledge 22 has a wedge-shape, the tongues 12 willslide onto the ledge 22. Alternatively, also only the tongues 12 or theledge 22 and the tongues 12 can have a wedge-shape. As shown in FIG. 4 ,the guard 10 will overlap the ledge 22 when it reaches a distalposition, exerting a force on the ledge 22 and thus on the distal end 20of the beam 16. For example, the guard 10 may press the ledge 22inwards. As visible best in FIG. 3 , the medicament container holder 14may be provided with a cut-out for this purpose.

As shown in FIG. 4 , the guard 10 may be configured such that it alsooverlaps a proximal portion of the lever, preferably, such that it alsooverlaps the proximal end 19 of the beam 16. For example, the guard maybe positioned radially outside the proximal end 19 of the beam 16. Sincethe proximal portion of the lever is overlapped by the guard, the levercannot pivot when a force is exerted on the distal end, for example, bytongues 12 exerting a force on the distal end 20 of the lever when theyoverlap ledge 22 and press the distal end 20 inwards. Thus the lever,preferably beam 16, will be tensioned due to the position of the guard10.

When the ledge 22 has been moved radially inwards as shown in FIG. 3 ,the proximally directed tongue 28 of the actuation locking member 24does not abut the ledge. The actuation locking member 24 is free to bemoved in the proximal direction. Thus, a dose of medicament can bedelivered by the push button 42 being pressed in the proximal direction,whereby the protrusions 40 will push the arms 30 and thus thering-shaped member 26 in the proximal direction, FIG. 4 . This movementof the push button may cause an activation of the medicament deliverydrive unit such that the ledges 60 of the arms 58 are moved out ofcontact with the plunger rod. The plunger rod may then be forced in theproximal direction by the spring 52 and may act on the stopper insidethe medicament container 70 for delivering a dose of medicament throughthe medicament delivery member at the dose delivery site. The proximalmovement of the ring-shaped member 26 causes its proximally directedtongue 28 to move in the proximal direction, whereby it may be movedover the ledge 22, since the latter is pressed inwards in the radialdirection. Actuation locking means (not shown) may be arranged to lockthe member 38 and thus the push button 42 in the proximal and depressedposition.

When performing the delivery, the proximal movement of the member 38causes it to slide along the arms 58. The arms 58 may then be free tomove in the outwardly radial direction into a through recess 39 on themember 38, which causes the hooks 60 to move out of contact or itsresilient engagement with the cut-outs of the spring-loaded plungermember. This in turn releases the spring-loaded plunger member to movein the proximal direction due to the force of the compressed drivespring 52. The movement of the spring-loaded plunger rod forces thestopper to move proximally and thereby expel the medicament through themedicament delivery member. When the stopper has reached its endposition, i.e. the proximal end position, inside the medicamentcontainer, the medicament delivery operation is completed. Theconnection of the arms 58 and the through recess 39 may provide themember 38 and thus the push button 42 to be locked in a proximal anddepressed position.

When the dose has been delivered, the device may be withdrawn from thedose delivery site. This in turn may cause the guard 10 to be moved inthe proximal direction by the spring 13. The proximal movement of thespring 13 will cause it to release the proximal end 19 of the beam 16,whereby the latter will flex outwards in the radial direction due to thetension built up in the beam 16. The lever, preferably beam 16, may thusreach the final position shown in FIG. 5 in which the lever restrictsthe movement of guard 10 in the distal direction. The proximal end 19 ofthe longitudinal beam 16 may be positioned between the distally directedtongues 12 of the guard 10, locking the guard 10 against movement in thedistal direction and allowing the device to be discarded safely.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, such illustration and descriptionare to be considered illustrative or exemplary and not restrictive. Itwill be understood that changes and modifications may be made by thoseof ordinary skill within the scope of the following claims. Inparticular, the present invention covers further embodiments with anycombination of features from different embodiments described above andbelow.

Furthermore, in the claims the word “comprising” does not exclude otherelements or steps, and the indefinite article “a” or “an” does notexclude a plurality. A single unit may fulfil the functions of severalfeatures recited in the claims. The terms “essentially”, “about”,“approximately” and the like in connection with an attribute or a valueparticularly also define exactly the attribute or exactly the value,respectively. Any reference signs in the claims should not be construedas limiting the scope.

1-16. canceled
 17. A medicament delivery device, comprising: a guardmovable between a proximal position and a distal position; an actuationlocking member; a medicament container holder arranged within the guard;and a locking mechanism comprising a lever, wherein a distal end of thelever includes a protrusion that directly contacts the guard to therebyrestrict movement of the guard in the proximal position prior toactuation of the medicament delivery device, and wherein the lever ispivotally mounted directly to the medicament container holder such thatthe lever pivots around a pivot axis of the lever in two directions. 18.A The medicament delivery device of claim 17, wherein the actuationlocking member surrounds the medicament container holder.
 19. A Themedicament delivery device of claim 17, wherein the lever is formedintegral with the medicament container holder.
 20. A The medicamentdelivery device of claim 17, wherein the actuation locking member is aring-shaped or sleeve-shaped member surrounding the medicament containerholder.
 21. A The medicament delivery device of claim 17, wherein thelever is connected to a middle portion of the medicament containerholder.
 22. A The medicament delivery device of claim 17, wherein thelever is put in a tensioned state by the guard when the guard is movedin a distal direction.
 23. A The medicament delivery device of claim 22,wherein the tensioned state of the lever causes the lever to release theguard to thereby enable the guard to transition from the proximalposition to the distal position.
 24. A The medicament delivery device ofclaim 17, wherein the guard and the actuation locking member areconfigured to contact less than the entire lever.
 25. A The medicamentdelivery device of claim 17, wherein the actuation locking membercomprises at least one proximally extending tongue, and wherein the atleast one proximally extending tongue is configured to contact the leveras the guard transitions from the proximal position to the distalposition.
 26. A The medicament delivery device of claim 17, wherein thelever comprises a longitudinally extending beam.
 27. A The medicamentdelivery device of claim 17, wherein the guard comprises at least twodistally directed tongues, wherein each of the at least two distallydirected tongues includes a proximal end directly attached to the guardand a distal free end extending away from the guard in a distaldirection.
 28. A The medicament delivery device of claim 27, wherein theat least two distally directed tongues are integral with a distal end ofthe guard.
 29. A The medicament delivery device of claim 17, wherein thelever is at least partly overlapped by the actuation locking member whenthe medicament delivery device is actuated.